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comparison src/com/tmate/hgkit/fs/ByteArrayDataAccess.java @ 51:9429c7bd1920 wrap-data-access

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Try DataAccess to reach revision data instead of plain byte arrays
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Sun, 16 Jan 2011 01:20:26 +0100
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50:f1db8610da62 51:9429c7bd1920
1 /*
2 * Copyright (c) 2011 Artem Tikhomirov
3 */
4 package com.tmate.hgkit.fs;
5
6 import java.io.IOException;
7
8 /**
9 *
10 * @author artem
11 */
12 public class ByteArrayDataAccess extends DataAccess {
13
14 private final byte[] data;
15 private final int offset;
16 private final int length;
17 private int pos;
18
19 public ByteArrayDataAccess(byte[] data) {
20 this(data, 0, data.length);
21 }
22
23 public ByteArrayDataAccess(byte[] data, int offset, int length) {
24 this.data = data;
25 this.offset = offset;
26 this.length = length;
27 pos = 0;
28 }
29
30 @Override
31 public byte readByte() throws IOException {
32 if (pos >= length) {
33 throw new IOException();
34 }
35 return data[offset + pos++];
36 }
37 @Override
38 public void readBytes(byte[] buf, int off, int len) throws IOException {
39 if (len > (this.length - pos)) {
40 throw new IOException();
41 }
42 System.arraycopy(data, pos, buf, off, len);
43 pos += len;
44 }
45
46 @Override
47 public void reset() {
48 pos = 0;
49 }
50 @Override
51 public long length() {
52 return length;
53 }
54 @Override
55 public void seek(long offset) {
56 pos = (int) offset;
57 }
58 @Override
59 public void skip(int bytes) throws IOException {
60 seek(pos + bytes);
61 }
62 @Override
63 public boolean isEmpty() {
64 return pos >= length;
65 }
66
67 //
68
69 // when byte[] needed from DA, we may save few cycles and some memory giving this (otherwise unsafe) access to underlying data
70 @Override
71 public byte[] byteArray() {
72 return data;
73 }
74 }